php2shell-scanner README

The project's README from github.com/assetnote/php2shell-scanner. As one markdown file: README.md.

php2shell-scanner

A command-line tool for detecting CVE-2026-109618 and CVE-2026-109619 in PHP applications.

How It Works

The scanner sends a minimal multipart control request followed by up to three crafted multipart probes. The probes use PHP array keys nested 62 levels deep and increase from 1 MiB to 20 MiB, matching the detection logic used by Assetnote's internal scanner.

A target is reported vulnerable when the probe produces a PHP memory-exhaustion error, a differential empty HTTP 500, a PHP-FPM worker failure, or an advertised PHP version known to be unpatched. Initial 5xx responses, common request-rejection statuses, and nonempty HTTP 500 responses without the PHP fatal-error signature are not treated as crash signals.

The scanner tests /index.php by default. A path supplied in the URL is preserved, and --path or --path-file can test custom paths. phpMyAdmin targets are automatically retested at /show_config_errors.php. Redirects are not followed.

SAPI Modes

The default --sapi auto mode applies both mod_php and PHP-FPM verdict rules, matching the combined behavior of Assetnote's postmodules. Use --sapi mod_php or --sapi fpm to restrict detection to a known SAPI.

Network Impact

Each tested path may receive a 42-byte control request and three probes totalling about 29 MiB. Probing stops as soon as the verdict is settled, and duplicate input URLs are scanned once.

Requirements

Installation

pip install -r requirements.txt

Usage

Scan a single host:

python3 scanner.py -u https://example.com

Scan a list of hosts:

python3 scanner.py -l hosts.txt

Scan with multiple threads and save results:

python3 scanner.py -l hosts.txt -t 20 -o results.json

Scan with custom headers:

python3 scanner.py -u https://example.com -H "Authorization: Bearer token" -H "Cookie: session=abc"

Scan a custom path:

python3 scanner.py -u https://example.com --path /phpinfo.php
python3 scanner.py -u https://example.com --path /index.php --path /admin.php
python3 scanner.py -u https://example.com --path-file paths.txt

Use only PHP-FPM verdict rules:

python3 scanner.py -u https://example.com --sapi fpm

Options

-u, --url         Single URL to check
-l, --list        File containing hosts (one per line)
-t, --threads     Number of concurrent threads (default: 10)
--timeout         Request timeout in seconds (default: 60)
-o, --output      Output file for results (JSON)
--all-results     Save all results, not just vulnerable hosts
-k, --insecure    Disable TLS certificate verification
-H, --header      Custom header (can be used multiple times)
-v, --verbose     Show verdict reasons and response snippets
-q, --quiet       Only output vulnerable hosts
--no-color        Disable colored output
--sapi            Verdict rules: auto, mod_php, or fpm (default: auto)
--path            Custom path to test (can be used multiple times)
--path-file       File containing paths to test (one per line)

Credits

The first, original discovery of php2shell is attributed to the Calif team. You can read their write up here: https://calif.io/php2shell/.

The scanner was built by the Assetnote Security Research Team using logic built for Searchlight's Exposure Platform.

Output

Results are printed to the terminal. When using -o, vulnerable hosts are saved to a JSON file with the verdict reason and redacted HTTP request/response evidence.

Limitations

On specific PHP configurations, the scanner may report a false positive when its multipart probe exceeds PHP's memory_limit. Patched and vulnerable versions can then return the same empty HTTP 500 response.

This was reproduced on patched PHP 8.4.27 with memory_limit values from 2M to 32M, and on PHP 8.3.36 at 128M when max_multipart_body_parts is set to 2785 or higher. The exact threshold may vary between builds.

When PHP does not disclose its version, the scanner cannot distinguish this safe post-patch OOM from the vulnerable pre-patch behavior. Results should therefore be verified against the installed PHP version and any vendor backports

php2shell-scanner (assetnote/php2shell-scanner)

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